1. Field of the Invention
This invention relates to an improved method for treating clay materials to prepare a super-active catalyst, the catalyst so prepared and low temperature catalytic conversion of organic materials therewith.
2. Discussion of Prior Art
The activation of naturally-occurring and/or synthetic clay-type materials by mineral acid washing or by thermal decomposition of the ammonium-exchanged form of said clay to prepare catalysts for high temperature reactions conducted at over 400.degree. C is known in the art (Chem. Rev., 385-399, 74, 1974). These materials were among the first of the cracking catalysts. They are most effective when largely in their hydrogen form with reaction temperatures in the range of 400.degree. C to 500.degree. C.
Activation of aluminosilicate zeolites by ion-exchange with ions such as rare rare earth and hydrogen for use in high temperature hydrocarbon conversion reactions is also known in the art.
By the present method, a raw clay, without having been heated to a temperature exceeding 100.degree. C, is ion-exchanged with transition metal ions, hydrogen ions, aluminum ions, ions of metals from Group IIB of the Periodic Table or a combination thereof at a temperature not exceeding 100.degree. C and the resulting exchanged clay material is exposed to a temperature of at least about 50.degree. C but not exceeding about 250.degree. C. This is believed novel, whereby high temperatures are avoided before, during and after ion exchange of the clay.
Catalytic conversion methods of the type to which this invention pertains are well known in the art. However, these methods over a clay catalyst at low temperature, e.g. 50.degree. C to 250.degree. C, have not been reported to produce significant conversions of charge stock. For instance, greater than 0.5 weight percent coversion in catalytic cracking of a hydrocarbon over a clay catalyst at lower than 400.degree. C has not been reported.
References showing the state of the art as related to the present invention include U.S. Pat. No. 2,480,627, which teaches reactivating used (and therefore heated to temperatures over 400.degree. C) clay catalysts, by introducing an alkali metal into said used clay and then base exchanging the alkali metal so introduced into said used clay with various other metals. The catalyst so reactivated is then taught to be effective in a high temperature (800.degree. F) catalytic conversion of gas oil. Other references showing the state of the related art but which fall short of teaching the present improved method and catalytic conversion processes include U.S. Pat. Nos. 3,515,679; 3,278,417; 2,982,717; 2,848,423; 2,825,699; 2,727,868; 2,862,874 and 2,744,057 and Great Britain Pat. Nos. 847,528 and 1,085,758.